1. Field of the Invention
The present invention relates generally to a portable terminal having a mass storage secondary memory such as a hard disk. More particularly, the present invention relates to a portable terminal having a mass storage secondary memory where high-speed data transfer and multitasking can be supported by using the mass storage secondary memory as a portable disk of an external apparatus, and to a method of supporting high-speed data transfer and multitasking for the portable terminal.
2. Description of the Related Art
Recent rapid advances in information and communications technologies have allowed a mobile communication subscriber to use a conventional portable terminal to obtain traditional communication services such as voice telephone services and data communication services such as electronic mail, web browsing, and visual chatting services over wireless data networks. The mobile communication subscriber can also download various contents such as music files, moving images, still images, and games from favorite content providers and store the downloaded contents in the portable terminal for present and future enjoyment.
A portable terminal with the additional functionality of a camcorder, camera, or a moving picture experts group (MPEG) audio layer 3 (MP3) player has been developed. Therefore, a mobile communication subscriber can now use a single portable terminal to capture still or moving images, store them in the portable terminal, reproduce them with the portable terminal, or download and reproduce MP3 files.
Since memory used to store data for a conventional portable terminal is provided on an internal circuit board, the capacity of the memory is preset during the manufacturing processes. Therefore, the amount of data that the user can store in the memory is limited by the preset capacity. For example, the quantity of music files or still and moving images capable of being stored in the memory will depend on the preset capacity.
The portable terminal may have a flash memory for storing control programs to control an operation and function of the portable terminal, and a random access memory (RAM) for running the control programs. The flash memory is a nonvolatile memory used to store user data files as well as the control programs. Consequently, there is a need for a portable terminal with a large-capacity memory corresponding to diverse functions of the portable terminal and a large amount of user data.
FIG. 1 is a block diagram illustrating the configuration of a conventional portable terminal with a mass storage secondary memory.
The portable terminal comprises a main controller 20 for controlling ordinary communication functions of the portable terminal, and a sub-controller 40 for controlling added functions regarding, for example, multimedia.
The portable terminal also comprises a communication module 32, a key input unit 34, a basic information memory 36, a coder/decoder (CODEC) 38, a display unit 44, and a multimedia information memory 46. The communication module 32 is used for external communication over wireless networks according to the control of the main controller 20 and the key input unit 34 inputs a user command. The basic information memory 36 stores data concerning ordinary communication functions of the portable terminal such as use of voice telephone services. The CODEC 38 codes and decodes input/output audio signals, the display unit 44 displays operation states of the portable terminal, and the multimedia information memory 46 stores data concerning added functions of the portable terminal.
Due to a storage capacity limit of the basic memory 36 and multimedia information memory 46, the portable terminal further comprises a hard disk 60, which is a mass storage secondary memory capable of storing a large amount of data. The hard disk 60 is connected through a buffer 52 and hard disk controller 54 to the sub-controller 40. The buffer 52 acts to selectively output received data to the hard disk controller 54 according to the control of the sub-controller 40. The hard disk controller 54 controls drive of the hard disk 60, and data read and write operations thereof. The hard disk controller 54 writes data input from the sub-controller 40 through the buffer 52 on the hard disk 60, and reads data stored on the hard disk 60 and transfers the read data to the sub-controller 40 in response to a command from the sub-controller 40.
The main and sub controllers 20 and 40 each comprise an interface to an external electronic device, and can be connected through the interface to the external electronic device to send or receive certain data to or from the external electronic device. That is, the main and sub controllers 20 and 40 comprise universal serial bus (USB) full speed (FS) interfaces 22 and 42, respectively. The main controller 20 and sub-controller 40 are connected to a USB interface of a computer 10 to send data to the computer 10 or to receive data from the computer 10. The USB FS interfaces 22 and 42 support the FS data rate of the USB version 2.0, whose maximum data rate is 12 Mbits/sec.
Therefore, the main controller 20 can be connected through the USB FS interface 22 to the computer 10 via a USB cable, and can send or receive data related to ordinary voice telephone services such as a telephone number file and a ring tone file to or from the computer 10 at a data rate of 12 Mbits/sec, respectively.
The sub-controller 40 can be connected through the USB FS interface 42 to the computer 10 via a USB cable, and can send or receive multimedia data such as MP3 music files and photographed images to or from the computer 10 at a data rate of 12 Mbits/sec, respectively.
The main and sub controllers 20 and 40 may set a portable disk mode, in which they store data received through the USB FS interfaces 22 and 42, respectively, on the hard disk 60.
FIG. 2 illustrates a data transfer path from the connected computer to the portable terminal. The illustrated data transfer path denotes a path for storing data received through the USB FS interface 22 of the main controller 20 on the hard disk 60.
Referring to FIG. 2, data is transmitted from the computer 10 via a USB cable through the USB FS interface 22 to the main controller 20. The data is then transmitted through the sub-controller 40, buffer 52, and hard disk controller 54 to the hard disk 60.
FIG. 3 illustrates another data transfer path from the connected computer to the portable terminal. The data transfer path denotes a path for storing data received through the USB FS interface 42 of the sub-controller 40 on the hard disk 60.
Referring to FIG. 3, data is transmitted from the computer 10 via a USB cable through the USB FS interface 42 to the sub-controller 40. The data is then transmitted through the buffer 52 and hard disk controller 54 to the hard disk 60.
When the hard disk 60 of the portable terminal is used as a portable disk of the computer 10 acting as a host, data transfer is performed under the control of the main controller 20 and/or sub-controller 40. This facilitates the blocking of task operations of the portable terminal other than the data transfer. That is, in the portable disk mode of the conventional portable terminal, data transmission and reception operations involving the hard disk 60 are possible. Therefore, the portable disk mode of the conventional portable terminal does not have the ability to support multitasking.
In the portable disk mode of the conventional portable terminal, data transfer between the computer 10 and the hard disk 60 is performed through the USB FS interface 22 of the main controller 20 or the USB FS interface 42 of the sub-controller 40. Data transferred in this manner results in the data transfer rate being lowered to the maximum FS data rate of 12 Mbits/sec and complex data transfer paths.